I. Field of the Invention
This invention relates to apparatus for the combined planting of seed and application of fertilizer.
II. Description of the Prior Art
It is well known that seed, e.g. for cereals or other crops, fares much better if an appropriate amount of fertilizer is buried in the soil when the seed is being planted. It is also known that the fertilizer should not be in contact with the seed, since it may then "burn" and destroy the seed, but should be separated from the seed by a thin soil layer and should advantageously be located beneath the seed where it will be contacted by the roots when the seed begins to sprout.
Many devices have been proposed in the past for simultaneously burying seed and fertilizer, but many of these do not locate the fertilizer below the seed, or are complex and expensive or readily become blocked when operated in damp ground. In the case of the known devices which locate the seed below the fertilizer, the main disadvantage seems to be that the digging of a furrow for the seed disturbs the furrow previously produced for the fertilizer, or vice versa, so a satisfactory and reliable result cannot be obtained, particularly in difficult soil conditions.
There is thus a need for simple and reliable apparatus of the above-mentioned kind which is capable of locating the fertilizer at a suitable distance below the seed and which can preferably be manufactured as an attachment for conventional seed drills.